We've always enjoyed lenticular (winky, blinky, flicker) images - especially the vintage ones. This really neat Vari-Vue lenticular features a conversion chart to help folks in the United States convert metric recipes to USA measurements and to help the rest of the world convert to the USA measurements. Of course, when this was created, there were other countries that were not metric as well.
Each measurement is converted to its metric (or in the case of temperature, it's Celsius) equivalent and vice-versa. This is accomplished as each is shown separately as you move the card and the angle of the flicker is changed back and forth. We had difficulty photographing both angles, so you'll just have to trust us on this one!
Although this card is not officially marked Vari-Vue on the back, it is represented in the 1970s Vari-Vue files. The card is approximately the size of a business card or credit card: 3-1/2 inches by 2 inches.